<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="utf-8">
	<meta http-equiv="x-ua-compatible" content="ie=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="examples-styles.css"/>

	<link rel="icon" href="favicon.ico" type="image/x-icon"/>
	<title>abcjs: Basic Synth Demo</title>

	<style>
		main {
			max-width: 770px;
			margin: 0 auto;
		}
		.row {
			display: flex;
			justify-content: space-between;
			align-items: flex-start;
		}
		.status {
			padding: 2px 10px 10px 10px;
			background-color: #f0f0f0;
			width:250px;
		}
        @media (prefers-color-scheme: dark) {
            .status {
                background-color: #000000;
            }
        }
	</style>

	<script src="../dist/abcjs-basic.js" type="text/javascript"></script>
	<script type="text/javascript">
		var abc = "T: Cooley's\n" +
			"M: 4/4\n" +
			"L: 1/8\n" +
			"R: reel\n" +
			"K: Emin\n" +
			"|:D2|EB{c}BA B2 EB|~B2 AB dBAG|FDAD BDAD|FDAD dAFD|\n" +
			"EBBA B2 EB|B2 AB defg|afe^c dBAF|DEFD E2:|\n" +
			"|:gf|eB B2 efge|eB B2 gedB|A2 FA DAFA|A2 FA defg|\n" +
			"eB B2 eBgB|eB B2 defg|afe^c dBAF|DEFD E2:|";

		function load() {
			// First draw the music - this supplies an object that has a lot of information about how to create the synth.
			// NOTE: If you want just the sound without showing the music, use "*" instead of "paper" in the renderAbc call.
			var visualObj = ABCJS.renderAbc("paper", abc, {
				responsive: "resize" })[0];

			// This object is the class that will contain the buffer
			var midiBuffer;

			var startAudioButton = document.querySelector(".activate-audio");
			var stopAudioButton = document.querySelector(".stop-audio");
			var explanationDiv = document.querySelector(".suspend-explanation");
			var statusDiv = document.querySelector(".status");

			startAudioButton.addEventListener("click", function() {
				startAudioButton.setAttribute("style", "display:none;");
				explanationDiv.setAttribute("style", "opacity: 0;");
				statusDiv.innerHTML = "<div>Testing browser</div>";
				if (ABCJS.synth.supportsAudio()) {
					stopAudioButton.setAttribute("style", "");

					// An audio context is needed - this can be passed in for two reasons:
					// 1) So that you can share this audio context with other elements on your page.
					// 2) So that you can create it during a user interaction so that the browser doesn't block the sound.
					// Setting this is optional - if you don't set an audioContext, then abcjs will create one.
					window.AudioContext = window.AudioContext ||
						window.webkitAudioContext ||
						navigator.mozAudioContext ||
						navigator.msAudioContext;
					var audioContext = new window.AudioContext();
					audioContext.resume().then(function () {
						statusDiv.innerHTML += "<div>AudioContext resumed</div>";
						// In theory the AC shouldn't start suspended because it is being initialized in a click handler, but iOS seems to anyway.

						// This does a bare minimum so this object could be created in advance, or whenever convenient.
						midiBuffer = new ABCJS.synth.CreateSynth();

						// midiBuffer.init preloads and caches all the notes needed. There may be significant network traffic here.
						return midiBuffer.init({
							visualObj: visualObj,
							audioContext: audioContext,
							millisecondsPerMeasure: visualObj.millisecondsPerMeasure()
						}).then(function (response) {
							console.log("Notes loaded: ", response)
							statusDiv.innerHTML += "<div>Audio object has been initialized</div>";
							// console.log(response); // this contains the list of notes that were loaded.
							// midiBuffer.prime actually builds the output buffer.
							return midiBuffer.prime();
						}).then(function (response) {
							statusDiv.innerHTML += "<div>Audio object has been primed (" + response.duration + " seconds).</div>";
							statusDiv.innerHTML += "<div>status = " + response.status + "</div>"
							// At this point, everything slow has happened. midiBuffer.start will return very quickly and will start playing very quickly without lag.
							midiBuffer.start();
							statusDiv.innerHTML += "<div>Audio started</div>";
							return Promise.resolve();
						}).catch(function (error) {
							if (error.status === "NotSupported") {
								stopAudioButton.setAttribute("style", "display:none;");
								var audioError = document.querySelector(".audio-error");
								audioError.setAttribute("style", "");
							} else
								console.warn("synth error", error);
						});
					});
				} else {
					var audioError = document.querySelector(".audio-error");
					audioError.setAttribute("style", "");
				}
			});

			stopAudioButton.addEventListener("click", function() {
				startAudioButton.setAttribute("style", "");
				explanationDiv.setAttribute("style", "");
				stopAudioButton.setAttribute("style", "display:none;");
				if (midiBuffer)
					midiBuffer.stop();
			});
		}
	</script>
</head>
<body onload="load()">
<main>
  <header>
    <img src="https://paulrosen.github.io/abcjs/img/abcjs_comp_extended_08.svg" alt="abcjs logo">
    <h1>Basic Synth</h1>
  </header>
	<div class="container">
		<div id="paper"></div>
		<p class="suspend-explanation">Browsers won't allow audio to work unless the audio is started in response to a
			user action. This prevents auto-playing web sites. Therefore, the
			following button is needed to do the initialization:</p>
		<div class="row">
			<div>
				<button class="activate-audio">Activate Audio Context And Play</button>
				<button class="stop-audio" style="display:none;">Stop Audio</button>
				<div class='audio-error' style="display:none;">Audio is not supported in this browser.</div>
			</div>
			<div class="status"></div>
		</div>
	</div>
</main>
</body>
</html>
